The automotive parts recycling industry produces goods that are entirely or partially based on components recovered from end-of-life products or manufacturing scrap. The process transforms recovered components into “like-new” goods, and yields important economic and environmental benefits. Remanufactured or recycled goods generally have the appearance, performance, and life expectancy of new goods. They meet the same performance standards as, and enjoy warranties similar or identical to, equivalent new goods. In short, remanufactured/recycled products are intended to be identical to products manufactured entirely from raw materials, new parts or components.
Automotive remanufacturing/recycling was roughly a $40 billion market in the U.S. in 2008, based on estimates by the Automotive Parts Remanufacturers Association (APRA). Total vehicle scrappage rate, defined as the ratio of vehicles reaching end-of-life (ELV) to the number of registered vehicles, reached 5.6 percent in 2008, according to R. L. Polk & Co. figures in its annual vehicle population report, based on 249 million registered vehicles. Therefore, each year, nearly 14 million vehicles that reach the end of their useful life are recycled.
Automotive recyclers can now recover nearly 80 percent of the total materials by weight from a vehicle; a motor vehicle contains today around 8-10 percent by weight of plastics (about 257-322 lbs/vehicle), but the proportion of plastic materials being recycled is still extremely low. One key reason is the wide variety of polymers used by the automotive industry: there are about 39 different types of basic plastics in a vehicle today. About 75 percent of plastics (by weight) are covered by 10 plastic grades. Although these polymers are technically recyclable, costs to separate and clean each polymer is much higher, in the vast majority of cases, than purchasing and processing virgin polymers.
Automotive interior soft trim parts are a good example because these multi-layer, multi-material constructions do not generally lend themselves to a straight recycling approach. On the contrary, they require complex, expensive, and usually uncompetitive disassembly and separation operations. This explains why today there are no known commercial recycling processes able to convert post-industrial or post-consumer automotive interior soft trim composites into finished trim panels for re-use in motor vehicles. Such parts include headliners and other interior trim and acoustical panels such as hood/wheelhouse liners, carpets, package trays, A, B, C pillars, visors and trunk trim components. These articles are complex composites of several materials including, but not limited to, nylon, polypropylene, polyester, filled EVA (ethylene vinyl acetate), cellulose films, semi-rigid/flexible thermosetting polyurethane foams, glass, cotton and in some cases natural fibers; these parts are ultimately disposed and discarded in landfills.
Because of their unique multi-layer, multi-material composite structures, headliners are generally viewed as the most difficult automotive interior trim part to recycle; consequently, they provide a good challenge to demonstrate the value and feasibility of new recycling technologies.
Techniques have been disclosed to recycle automotive components, but they rely upon water-based adhesives and intermediate pre-preg sheets, which raises cost and complexity. According to U.S. Pat. Nos. 5,807,513 and 6,110,580, for example, a water-borne binder or adhesive is required to provide binder coverage to all pieces of fluff. Once the mixture of fluff, binder reagent and water are mixed, it must be placed in a cold mold where the blend is formed into a pre-preg sheet. Subsequently, this pre-preg sheet is compressed at elevated temperatures to produce a finished composite trim panel. In addition to requiring another processing step to produce the pre-peg sheet, another shortcoming of existing methods is a shorter pot-life potentially arising from the vigorous mixing of the binder reagent with water and the fluff at room temperature, which could lead to the premature reaction of the binder with water.
It would be therefore highly desirable to develop a rapid, efficient and cost-effective procedure to recycle both manufacturing scrap and post-consumer automotive interior trim parts into a wide variety of panels for subsequent use in vehicles.